WARNINGS
IBRANCE may cause serious side effects, including:
Low white blood cell counts (neutropenia). Low white blood cell counts are very common when taking IBRANCE and may cause serious infections that can lead to death. Your healthcare provider should check your white blood cell counts before and during treatment.
If you develop low white blood cell counts during treatment with IBRANCE, your healthcare provider may stop your treatment, decrease your dose, or may tell you to wait to begin your treatment cycle. Tell your healthcare provider right away if you have signs and symptoms of low white blood cell counts or infections such as fever and chills.
Lung problems (pneumonitis). IBRANCE may cause severe or life-threatening inflammation of the lungs during treatment that can lead to death. Tell your healthcare provider right away if you have any new or worsening symptoms, including:
• chest pain
• cough with or without mucus
• trouble breathing or shortness of breath
Your healthcare provider may interrupt or stop treatment with IBRANCE completely if your symptoms are severe.
What should I tell my healthcare provider before taking IBRANCE?
Before taking IBRANCE, tell your healthcare provider about all of your medical conditions, including if you:
• have fever, chills, or any other signs or symptoms of infection.
• have liver or kidney problems.
• have any other medical conditions.
• are pregnant, or plan to become pregnant. IBRANCE can harm your unborn baby.
O Females who are able to become pregnant should use effective birth control during treatment and for at least 3 weeks after the last dose of IBRANCE. Your healthcare provider may ask you to take a pregnancy test before you start treatment with IBRANCE.
O Males with female partners who can become pregnant should use effective birth control during treatment with IBRANCE for at least 3 months after the last dose of IBRANCE.
O Talk to your healthcare provider about birth control methods that may be right for you during this time.
O If you become pregnant or think you are pregnant, tell your healthcare provider right away.
• are breastfeeding or plan to breastfeed. It is not known if IBRANCE passes into your breast milk. Do not breastfeed during treatment with IBRANCE and for 3 weeks after the last dose.
Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. IBRANCE and other medicines may affect each other causing side effects.
Know the medicines you take. Keep a list of them to show your healthcare provider or pharmacist when you get a new medicine.
USES
IBRANCE is a prescription medicine used:
In adults to treat hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer that has spread to other parts of the body (metastatic) in combination with:
• an aromatase inhibitor as the first hormonal based therapy, or
• fulvestrant in people with disease progression following hormonal therapy.
In adults with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative and with an abnormal phosphatidylinositol-3-kinase catalytic subunit alpha (PIK3CA) gene breast cancer that has spread to nearby tissue or lymph nodes (locally advanced), or to other parts of the body (metastatic) in combination with:
• inavolisib and fulvestrant in people with disease progression during or after adjuvant hormonal therapy.
It is not known if IBRANCE is safe and effective in children.
HOW TO USE
How should I take IBRANCE?
• Take IBRANCE exactly as your healthcare provider tells you.
• Take IBRANCE with food.
• IBRANCE should be taken at about the same time each day.
• Swallow IBRANCE capsules whole. Do not chew, crush or open IBRANCE capsules before swallowing them.
• Do not take any IBRANCE capsules that are broken, cracked, or that look damaged.
• Avoid grapefruit and grapefruit products during treatment with IBRANCE. Grapefruit may increase the amount of IBRANCE in your blood.
• Do not change your dose or stop taking IBRANCE unless your healthcare provider tells you.
• If you miss a dose of IBRANCE or vomit after taking a dose of IBRANCE, do not take another dose on that day. Take your next dose at your regular time.
• When IBRANCE is used in combination with inavolisib and fulvestrant, or an aromatase inhibitor, also read the Patient Information for the prescribed products.
What are the possible side effects of IBRANCE?
IBRANCE may cause serious side effects. See "What is the most important information I should know about IBRANCE?"
The most common side effects of IBRANCE when used with either letrozole or fulvestrant include:
• Low red blood cell counts and low platelet counts are common with IBRANCE. Call your healthcare provider right away if you develop any of these symptoms during treatment:
o dizziness
o shortness of breath
o weakness
o bleeding or bruising more easily
o nosebleeds
• infections (see "What is the most important information I should know about IBRANCE?")
• tiredness
• nausea
• sore mouth
• abnormalities in liver blood tests
• diarrhea
• hair thinning or hair loss
• increased blood creatinine
The most common side effects of IBRANCE when used in combination with inavolisib plus fulvestrant include:
• high blood sugar levels leading to excessive thirst and urination
• sore mouth
• diarrhea
• decreased white blood cell counts, red blood cell counts, and platelet counts
• decreased blood levels of calcium, potassium, sodium, and magnesium
• increased creatine blood levels
• tiredness
• abnormalities in liver blood tests
• nausea
• rash
• loss of appetite
• COVID-19 infection
• headache
IBRANCE may cause fertility problems in males. This may affect your ability to father a child. Talk to your healthcare provider about family planning options before starting IBRANCE if this is a concern for you.
Tell your healthcare provider if you have any side effect that bothers you or that does not go away.
These are not all of the possible side effects of IBRANCE.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
General information about the safe and effective use of IBRANCE
Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use IBRANCE for a condition for which it was not prescribed. Do not give IBRANCE to other people, even if they have the same symptoms you have. It may harm them. You can ask your pharmacist or healthcare provider for more information about IBRANCE that is written for health professionals.
125 mg capsules: opaque, hard gelatin capsules, size 0, with caramel cap and body, printed with white ink "Pfizer" on the cap, "PBC 125" on the body.
100 mg capsules: opaque, hard gelatin capsules, size 1, with caramel cap and light orange body, printed with white ink "Pfizer" on the cap, "PBC 100" on the body.
75 mg capsules: opaque, hard gelatin capsules, size 2, with light orange cap and body, printed with white ink "Pfizer" on the cap, "PBC 75" on the body.
OVERDOSE
Please call your healthcare provider for more information.
MISSED DOSE
If you miss a dose of IBRANCE or vomit after taking a dose of IBRANCE, do not take another dose on that day. Take your next dose at your regular time.
STORAGE
How should I store IBRANCE?
• Store IBRANCE at 68-degrees F to 77-degrees F (20-degrees C to 25-degrees C).
Keep IBRANCE and all medicines out of the reach of children.
NOTES
Medication Guide: revision date 03/2023
Prescribing Information: revision date 09/2025
Palbociclib is primarily metabolized by CYP3A and sulfotransferase (SULT) enzyme SULT2A1. In vivo, palbociclib is a time-dependent inhibitor of CYP3A.
Agents That May Increase Palbociclib Plasma Concentrations
Effect of CYP3A Inhibitors
Coadministration of a strong CYP3A inhibitor (itraconazole) increased the plasma exposure of palbociclib in healthy subjects by 87%. Avoid concomitant use of strong CYP3A inhibitors (e.g., clarithromycin, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telaprevir, telithromycin, and voriconazole). Avoid grapefruit or grapefruit juice during IBRANCE treatment. If coadministration of IBRANCE with a strong CYP3A inhibitor cannot be avoided, reduce the dose of IBRANCE.
Agents That May Decrease Palbociclib Plasma Concentrations
Effect of CYP3A Inducers
Coadministration of a strong CYP3A inducer (rifampin) decreased the plasma exposure of palbociclib in healthy subjects by 85%. Avoid concomitant use of strong CYP3A inducers (e.g., phenytoin, rifampin, carbamazepine, enzalutamide, and St John's Wort).
Drugs That May Have Their Plasma Concentrations Altered by Palbociclib
Coadministration of midazolam with multiple doses of IBRANCE increased the midazolam plasma exposure by 61%, in healthy subjects, compared to administration of midazolam alone. The dose of the sensitive CYP3A substrate with a narrow therapeutic index (e.g., alfentanil, cyclosporine, dihydroergotamine, ergotamine, everolimus, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus) may need to be reduced, as IBRANCE may increase its exposure.
See the section WARNINGS above.
